The Molluscum Contagiosum virus is being replicated in tissue culture. The DNA replication cycle is being investigated. The components of the virion, the DNA, the proteins and peptides and membrane substructures are being isolated and characterized. Antiserum to the components are being stimulated. The virion in vivo causes hypertrophy and hyperplasia of adjacent cells and a diffusable peptide or protein is being sought which can induce either hyperplasia or hypertrophy in uninfected cells. We are seeking a good plaque assay method for the virus.